BS ISO 21501-1:2009

Foreword
Introduction
1 Scope
2 Terms and definitions
3 Requirements
  3.1 Size range
  3.2 Counting efficiency
      3.2.1 General
      3.2.2 Lower size limit
      3.2.3 Upper size limit
  3.3 Size resolution
  3.4 Sizing accuracy
  3.5 Sampling flow rate
  3.6 Effective detection flow rate
  3.7 Maximum particle number concentration
4 Test method
  4.1 Size calibration
  4.2 Effective detection flow rate
  4.3 Maximum particle number concentration
  4.4 Size resolution
  4.5 Counting efficiency
Annex A (informative) - Principle of the instruments
Annex B (informative) - Particle size standards
Annex C (informative) - Effects of the LSAS parameters
        on the particle size and particle number
        concentration determination
Annex D (informative) - Representative sampling
Annex E (informative) - Example of an LSAS calibration with
        DEMS-classified PSL particles
Bibliography

Describes characteristics of a light scattering aerosol spectrometer (LSAS) which is used for measuring the size, number concentration and number/size distribution of particles suspended in a gas.

This part of ISO21501 specifies characteristics of a light scattering aerosol spectrometer (LSAS) which is used for measuring the size, number concentration and number/size distribution of particles suspended in a gas. The light scattering technique described in this part of ISO21501 is based upon single particle measurements. The size range of particles measured by this method is between approximately 0,06µm to 45µm in diameter.

Instruments that conform to this part pf ISO21501 are used for the determination of the particle size distribution and particle number concentration at relatively high concentrations of up to 10¹¹ particles/m³.

Application fields include:

• characterization of metered dose inhalers (MDI), dry powder inhalers (DPI) and nebulizers in pharmacy;

• production control of active agents;

• cut-off determination: impactors, cyclones and impingers;

• atmospheric aerosols: bio-aerosols, stables/composting facilities, nebulized droplets, measurements in street tunnels;

• fractional separation efficiency determination of filters.

For the above-mentioned applications, aerosol spectrometers should determine the particle size distribution, particle number concentration, size resolution and sizing accuracy as accurately as possible. These aerosol spectrometers are not suitable for the classification of clean rooms.